Here is a quote from the Replay Cinema support article:
Hosting and maintaining the Replay Cinema is very costly. Due to this, and the fact that the Replay Cinema is very much an ‘extra’, on top of all of our free content, we have decided to charge a small fee to access it.
In my opinion, I don’t see The Hive changing the replay cinema to be free access in the future. I’m sure that the replay cinema is very profitable for the server, so if they made it free, they would be losing a lot of money.